The present disclosure generally relates to an automated crack detection system and method for a vehicle closure and more particularly relates to an automated crack detection system and method that monitors acoustic emissions during an open and close durability test of the vehicle closure for determining a crack initiation potential of a vehicle closure.
It is known to monitor critical areas of a vehicle closure, such as a door, tailgate or the like, for fatigue failures occurring during repeated opening and closing (i.e., durability testing) of the vehicle closure. Fatigue failure can be determined by the appearance of a crack in the vehicle closure and the durability of the vehicle closure can be measured by counting the number of repeated openings and closing of the vehicle closure prior to the appearance of the crack. Thus, for example, a vehicle closure can be said to fail due to fatigue when a crack appears after a number of closings of the vehicle closure.
The current method for finding a crack in the vehicle closure requires invasive physical checks to be performed on the vehicle closure. For example, a vehicle closure undergoing durability testing may have to be removed from the vehicle to which it was mounted and/or cut open (i.e., undergo a tear-down) to search for cracks which likely prevents reuse of the vehicle closure. This is a cumbersome process that is time consuming and expensive. There are also difficulties associated with determining precisely when or after how many openings and closings (i.e., cycles) to perform a crack check.
Moreover, any cracks forming in the vehicle closure must typically propagate to a considerable size before they can be detected under current durability testing and monitoring methods. As a result, it is often difficult to determine when a crack first forms in the vehicle closure and information concerning propagation of the crack immediately after initial formation is generally unavailable. Oftentimes, multiple durability tests are performed on several vehicle closures of a common design so the vehicle closures can be removed and/or cut open at varying stages of the durability test in an attempt to more accurately determine when crack formation begins. This causes further labor and material costs to be incurred during durability testing of vehicle closures. Accurately determining the timing of crack initiation during a durability test is also important to improve the correlation of physical tests with Computer Aided Engineering (CAE) simulations. Improved simulation accuracy can reduce the dependence on prototype testing, and thereby reduce the cost of the development of vehicle closure systems.